1. Field of the Invention
The invention relates to a strand guide, in particular for a steel slab continuous casting installation having a plurality of segments which support a strand on two opposite sides with support elements, wherein the support elements are arranged in a lower frame and an upper frame and wherein the frames are formed for guiding the strand in a conveying direction.
2. Description of the Prior Art
A strand guide for a continuous casting installation of this type is disclosed in EP 0 963 263 B1. The strand guide has a plurality of support segments which form a casting bow having opposite rows of guide and drive rollers.
The rollers are supported in an upper frame and a lower frame. At one end of a frame, there are arranged two guide rods equidistantly spaced from the central axis. This connection guide rod concept of segments is used in continuous casting installations, i.e., for strand guidance. The connection guide rods are arranged in a segment on each side of the segment as guide means of the upper frame.
Such a solution, can be seen in FIGS. 2 and 3 which show a plan view and a side view of a segment of a strand guide. The segment 2 of the strand guide has a lower frame 8 and an upper frame 9 which are provided with respective support, elements in form of rollers 6 and 7. The rollers 6, which are arranged in the lower frame 8, guide the lower side 4 of the cast strand 3, the rollers 7, which are arranged in the upper frame 9, guide, correspondingly, the upper side 5 of the cast strand. The upper frame 9 is connected with the lower frame 8 by two guide rods 11 and 12 which displace the upper frame 9 relative to the lower frame 8.
A similar solution is shown in DE 102 25 924 C2. Here, also, the frames are connected with each other by connection means which here can be formed as spring strips. A further similar solution is disclosed in DE-AS 1 171 119.
The drawback of the known solutions, when connection guide rods are used, consists in that the support of the strand by rollers after mounting of the segment is not changeable which is unfavorable with regard to distribution of the strand support with rollers or bending points or straightening points dependent on the cast thickness format. Further, a so-called bulging effect can be easily produced in the meniscus and which is possible, at fixed roller spacings and roller positions, as a result retroactive effect of strand displacement.
A further negative effect of known installations consists in that mounting and dismounting of a segment, which is required from time to time, is problematic because of space ratios, only little place is available for removal or installation of a frame.
Finally, a further drawback consists in that after mounting of a segment, the precise alignment of the upper frame with the lower frame becomes fixed. Changing this alignment, which sometimes is desirable, can be brought off with much difficulty.
Accordingly, an object of the present invention is to so improve a strand guide of the type described above so that the above-mentioned drawbacks are eliminated or prevented. A better strand support with rollers should become possible to achieve a better support, bending and/or straightening condition. Further, bulging effect should be eliminated. Mounting and dismounting conditions of segments can likewise be improved. Finally, it should be possible to achieve a precise alignment of the upper and lower frames with simple means.